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AIDS is an Acronym and initialism|acronym for Acquired Immunodeficiency Syndrome or Acquired Immune Deficiency Syndrome and is defined as a collection of symptoms and infections resulting from the depletion of the immune system caused by infection with the HIV|human immunodeficiency virus, commonly called HIV (Marx et al., 1982). Although treatments for both AIDS and HIV exist to slow the virus' progression in a human patient, there is no known cure. The rate of clinical disease progression varies widely between individuals and has been shown to be affected by many factors such as host susceptibility (Clerici et al., 1996; Morgan et al., 2002a; Tang et al., 2003), health care and co-infections (Morgan et al., 2002b; Lawn et al., 2004), and peculiarities of the viral strain (Campbell et al., 2004; Campbell et al., 2005; Senkaali et al., 2005). AIDS is thought to have originated in sub-Saharan Africa (Gao et al., 1999) during the twentieth century and is now a global epidemic. UNAIDS and the WHO estimate that AIDS has killed more than 25 million people since it was first recognized in 1981, making it one of the most destructive epidemics in recorded history. In 2005 alone, AIDS claimed an estimated 3.1 million (between 2.8 and 3.6 million) of which more than half a million (570,000) were children (UNAIDS, 2005). In countries where there is access to antiretroviral drug|antiretroviral treatment, both mortality and morbidity of HIV infection have been reduced (Palella et al., 1998). However, side-effects of these antiretrovirals have also caused problem such as lipodystrophy, dyslipidaemia, insulin resistance and an increase in cardiovascular risks (Montessori et al., 2004), or viral escape and viral resistance|resistance linked to non-observance of the antiretroviral regimen (Becker et al., 2002). The symptoms of AIDS are primarily the result of conditions that do not normally develop in individuals with healthy immune systems. Most of these conditions are infections caused by bacteria, virus|viruses, fungus|fungi, parasites, and other organisms. Opportunistic infections are common in people with AIDS (Holmes et al., 2003). Nearly every organ system is affected. People with AIDS also have an increased risk to develop various cancers such as Kaposi sarcoma, cervical cancer and cancers of the immune system known as lymphomas. Common symptoms are fevers, sweats (particularly at night), swollen glands, chills, weakness, and weight loss (Guss, 1994a; 1994b). After the diagnosis of AIDS is made, the current average survival time with antiretroviral therapy is estimated to be between 4 to 5 years (Schneider et al., 2005). Without this therapy, progression to death normally occurs within a year (Morgan et al., 2002b). Most patients die from opportunistic infections or malignancies associated with the progressive failure of the immune system (Lawn et al., 2004). AIDS and HIV case definitions Since 1982, many different definitions have been developed for epidemiological surveillance such as the Bangui definition and the 1994 expanded World Health Organization AIDS case definition. However, these were never intended to be used for clinical staging of patients, for which they are neither sensitive nor specific. The World Health Organizations (WHO) staging system for HIV infection and disease, using clinical and laboratory data, can be used in developing countries and the Centers for Disease Control and Prevention|Centers for Disease Control (CDC) Classification System can be used in developed nations. WHO Disease Staging System for HIV Infection and Disease In 1990, the World Health Organization (WHO) grouped these infections and conditions together by introducing a staging system for patients infected with HIV-1 (WHO, 1990). This was updated in September 2005. Most of these conditions are opportunistic infections that can be easily treated in healthy people.
Seesubarticle|WHO Disease Staging System for HIV Infection and Disease CDC Classification System for HIV Infection In the USA, the definition of AIDS is goverened by the Centers for Disease Control and Prevention (CDC). In 1993, the CDC expanded their definition of AIDS to include healthy HIV positive people with a CD4 positive T cell count of less than 200 per ??l of blood. The majority of new AIDS cases in the United States are reported on the basis of a low T cell count in the presence of HIV infection (MMWR, 1992). Seesubarticle|CDC Classification System for HIV Infection Clinical symptoms of AIDS The major pulmonary illnesses =Pneumocystis jiroveci pneumonia= Pneumocystis jiroveci pneumonia (originally known as Pneumocystis carinii pneumonia, often abbreviated PCP) is relatively rare in normal, immunocompetent people but common among HIV-infected individuals. Before the advent of effective treatment and diagnosis in Western countries it was a common immediate cause of death. In developing countries, it is still one of the first indications of AIDS in untested individuals, although it does not generally occur unless the CD4 count is less than 200 per ??l (Feldman, 2005). =Tuberculosis= Among infections associated with HIV, tuberculosis (TB) is unique in that it may be transmitted to immunocompetent persons via the respiratory route, is easily treatable once identified, may occur in early-stage HIV disease, and is preventable with drug therapy. However, multi-drug resistance is a potentially serious problem. Even though its incidence has declined because of the use of directly observed therapy and other improved practices in Western countries, this is not the case in developing countries where HIV is most prevalent. In early-stage HIV infection (CD4 count >300 cells per ??l), TB typically presents as a pulmonary disease. In advanced HIV infection, TB may present atypically and extrapulmonary TB is common infecting bone marrow, bone, urinary and gastrointestinal tracts, liver, regional lymph nodes, and the central nervous system (Decker and Lazarus, 2000). The major gastro-intestinal illnesses =Esophagitis= Esophagitis is an inflammation of the lining of the lower end of the esophagus (gullet or swallowing tube leading to the stomach). In HIV infected individuals, this could be due to fungus (candidiasis), virus (herpes simplex-1 or cytomegalovirus). In rare cases, it could be due to mycobacteria (Zaidi and Cervia, 2002). =Unexplained chronic diarrhea= In HIV infection, there are many possible causes of diarrhea, including common bacterial (Salmonella, Shigella, Listeria, Campylobacter, or Escherichia coli) and parasitic infections, and uncommon opportunistic infections such as cryptosporidiosis, microsporidiosis, Mycobacterium avium complex (MAC) and cytomegalovirus (CMV) colitis. Diarrhea may follow a course of antibiotics (common for Clostridium difficile). It may also be a side effect of several drugs used to treat HIV, or it may simply accompany HIV infection, particularly during primary HIV infection. In the later stages of HIV infection, diarrhea is thought to be a reflection of changes in the way the intestinal tract absorbs nutrients, and may be an important component of HIV-related wasting (Guerrant et al., 1990). The major neurological illnesses =Toxoplasmosis= Toxoplasmosis is a disease caused by the single-celled parasite called Toxoplasma gondii. T. gondii usually infects the brain causing toxoplasma encephalitis. It can also infect and cause disease in the eyes and lungs (Luft and Chua, 2000). =Progressive multifocal leukoencephalopathy= Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease, in which the myelin sheath covering the axons of nerve cells is gradually destroyed, impairing the transmission of nerve impulses. It is caused by a virus called JC virus which occurs in 70% of the population in latent form, causing disease only when the immune system has been severly weakened, as is the case for AIDS patients. It progresses rapidly, usually causing death within months of diagnosis (Sadler and Nelson, 1997). =HIV-associated dementia= HIV-1 associated dementia (HAD) is a metabolic encephalopathy induced by HIV infection and fueled by immune activation of brain macrophages and microglia (Gray et al., 2001). These cells are actively infected with HIV and secrete neurotoxins of both host and viral origin. Specific neurologic impairments are manifested by cognitive, behavioral, and motor abnormalities that occur after years of HIV infection and is associated with low CD4+ T cell levels and high plasma viral loads. Prevalence is between 15-30% in Western countries (Heaton et al., 1995; White et al., 1995) and has only been seen in 1-2% of India based infections (Satischandra et al., 2000; Wadia et al., 2001). Since the beginning of the epidemic, three main transmission routes of HIV have been identified:
HIV has been found in the saliva, tears and urine of infected individuals, but due to the low concentration of virus in these biological liquids, the risk is considered to be negligible. Image:R402a1t1.gif|frame|right|CDC 2005 The diverse transmission routes of HIV are well-known and established. Also well-known is how to prevent transmission of HIV. However, recent epidemiological and behavioral studies in Europe and North America have suggested that a substantial minority of young people continue to engage in high-risk practices and that despite HIV/AIDS knowledge, young people underestimate their own risk of becoming infected with HIV (Dias et al., 2005). However, transmission of HIV between intravenous drug users has clearly decreased and HIV transmission by blood transfusion has become almost obsolete in this population. Prevention of sexual transmission of HIV Underlying science
Prevention strategies During a sexual act, only condoms, be they male or female, can reduce the chances of infection with HIV and other STIs and the chances of becoming pregnant. They must be used during all penetrative sexual intercourse with a partner who is HIV positive or whose status is unknown (Cayley, 2004). The effective use of condoms and screening of blood transfusion in North America, Western and Central Europe is credited with the low rates of AIDS in these regions. Adopting these effective prevention methods in other regions has proved controversial and difficult. Some claim this is in part because of the strong influence of the Vatican, which opposes the use of condoms. Image:ThreeColoredRolledUpCondoms.jpg|thumb|right|Condoms in many colors
With consistent and correct use of condoms, there is a very low risk of HIV infection. Studies on couples where one partner is infected show that with consistent condom use, HIV infection rates for the uninfected partner are below 1% per year http://www.wpro.who.int/media_centre/fact_sheets/fs_200308_Condoms.htm. Governmental programs The U.S. government and U.S. health organizations both endorse the ABC Approach to lower the risk of acquiring AIDS during sex:
This approach has been very successful in Uganda, where HIV prevalence has decreased from 15% to 5%. However, the ABC approach is far from all that Uganda has done, as "Uganda has pioneered approaches towards reducing stigma, bringing discussion of sexual behavior out into the open, involving HIV-infected people in public education, persuading individuals and couples to be tested and counseled, improving the status of women, involving religious organizations, enlisting traditional healers, and much more." (Edward Green, Harvard medical anthropologist). Also, it must be noted that there is no conclusive proof that abstinence-only programs have been successful in any country in the world in reducing HIV transmission. This is why condom use is heavily co-promoted. There is also considerable overlap with the CNN Approach. This is:
The ABC approach has been criticized, because a faithful partner of an unfaithful partner is at risk of AIDS http://www.economist.com/opinion/displayStory.cfm?story_id=4223619. Many think that the combination of the CNN approach with the ABC approach will be the optimum prevention platform. Circumcision Current research is clarifying the relationship between male circumcision and HIV in differing social and cultural contexts. UNAIDS believes that it is premature to recommend male circumcision services as part of HIV prevention programmes http://www.who.int/mediacentre/news/releases/2005/pr32/en/. Moreover, South African medical experts are concerned that the repeated use of unsterilised blades in the ritual circumcision of adolescent boys may be spreading HIV. http://allafrica.com/stories/200507070803.html Prevention of blood or blood product route of HIV transmission Underlying science
Prevention strategies
Mother to child transmission Underlying science
Prevention strategies
There is currently no cure or vaccine for HIV or AIDS. Infection with HIV leads to AIDS and ultimately death. However, in western countries, most patients survive many years following diagnosis because of the availability of the highly active antiretroviral therapy HAART (Schneider et al., 2005). In the absence of HAART, progression from HIV infection to AIDS occurs at a median of between nine to ten years and the median survival time after developing AIDS is only 9.2 months (Morgan et al., 2002b). HAART dramatically increases the time from diagnosis to death and research continues in drug treatments and vaccine development. Current optimal HAART options consist of combinations ("cocktails") consisting of at least three drugs belonging to at least two types, or "classes," of anti-retroviral agents. Typical regimens consist of two nucleoside analogue reverse transcriptase inhibitors (NRTIs) plus either a protease inhibitor (pharmacology)|protease inhibitor or a non nucleoside reverse transcriptase inhibitor (NNRTI). This treatment is frequently referred to as HAART (highly-active anti-retroviral therapy). http://www.hab.hrsa.gov/tools/HIVpocketguide05/PktGARTtables.htm#ARTtable3 Anti-retroviral treatments, along with medications intended to prevent AIDS-related opportunistic infections, have played a part in delaying complications associated with AIDS, reducing the symptoms of HIV infection, and extending patients' life spans. Over the past decade the success of these treatments in prolonging and improving the quality of life for people with AIDS has improved dramatically. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12646794&query_hl=5, http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12957089&query_hl=9. However, treatment guidelines are changing constantly. The http://www.who.int/hiv/pub/prev_care/en/arvrevision2003en.pdf current guidelines for antiretroviral therapy from the World Health Organization reflect the 2003 changes to the guidelines and recommend that in resource-limited settings (i.e., developing nations), HIV-infected adults and adolescents should start ARV therapy when HIV-infection has been confirmed and one of the following conditions is present:
The U.S. Department of Health and Human Services, the federal agency responsible for overseeing HIV/AIDS healthcare policies in the United States, http://aidsinfo.nih.gov/ContentFiles/AdultandAdolescentGL.pdf stated October 6, 2005that:
The preferred initial regimens are either:
The DHHS also recommends that doctors should assess the viral load, rapidity in CD4 decline, and patient readiness while deciding when to begin treatment. http://aidsinfo.nih.gov/ContentFiles/AdultandAdolescentGL.pdf There are several concerns about antiretroviral regimens. The drugs can have serious side effects (Saitoh et al., 2005). Regimens can be complicated, requiring patients to take several pills at various times during the day. If patients miss doses, drug resistance can develop (Dybul et al., 2002) Also, anti-retroviral drugs are costly, and the majority of the world's infected individuals do not have access to medications and treatments for HIV and AIDS. Research to improve current treatments includes decreasing side effects of current drugs, simplifying drug regimens to improve adherence, and determining the best sequence of regimens to manage drug resistance. Seesubarticle2|HIV vaccine|Antiretroviral drug Alternative medicine Ever since AIDS entered the public consciousness, various forms of alternative medicine have been used to try to treat its symptoms. In the first decade of the epidemic when no useful conventional treatment was available, a large number of people with AIDS experimented with alternative medicine|alternative therapies (massage, herbal and flower remedies and acupuncture). However, none of these have been proven to have any positive effect in treating HIV. Interest in these therapies has declined over the past decade as conventional treatments have improved. People with AIDS, like people with other illnesses such as cancer, also sometimes use marijuana to treat pain, combat nausea and stimulate appetite. Nearly half of those infected with HIV don't know that they are infected until they are diagnosed with AIDS. HIV test kits are used to screen donor blood and blood products, and to diagnose, treat and monitor individuals with HIV. HIV tests detect HIV antibodies, HIV antigens or HIV RNA in serum, plasma, oral fluid, dried blood spot or urine of patients. details|HIV test UNAIDS and the WHO estimate that AIDS has killed more than 25 million people since it was first recognized in 1981, making it one of the most destructive epidemics in recorded history. Despite recent, improved access to antiretroviral treatment and care in many regions of the world, the AIDS epidemic claimed an estimated 3.1 million (between 2.8 and 3.6 million) lives in 2005 of which more than half a million (570,000) were children (UNAIDS, 2005). Globally, between 36.7 and 45.3 million people are currently living with HIV (UNAIDS, 2005). In 2005, between 4.3 and 6.6 million people were newly infected and between 2.8 and 3.6 million people with AIDS died, an increase from 2004 and the highest number since 1981. AIDS_pandemic#Sub-Saharan_Africa|Sub-Saharan Africa remains by far the worst-affected region, with an estimated 23.8 to 28.9 million people currently living with HIV. More than 60% of all people living with HIV are in sub-Saharan Africa, as are more than three quarters (76%) of all women living with HIV. http://www.unaids.org/wad2004/EPIupdate2004_html_en/Epi04_03_en.htm#P28_3962 AIDS_pandemic#South_and_South-East_Asia|South & South East Asia are second most affected with 15%. AIDS accounts for the deaths of 500,000 children. The http://www.worldbank.org/oed/aids/main_report.html latest evaluation report of the World Bank's Operations Evaluation Department assesses the development effectiveness of the World Bank's country-level HIV/AIDS assistance defined as policy dialogue, analytic work, and lending with the explicit objective of reducing the scope or impact of the AIDS epidemic. This is the first comprehensive evaluation of the World Bank's HIV/AIDS support to countries, from the beginning of the epidemic through mid-2004. Because the Bank's assistance is for implementation of government programs by government, it provides important insights on how national AIDS programs can be made more effective. details|AIDS pandemic The official date for the beginning of the AIDS epidemic is marked as June 18, 1981, when the U.S. Centers for Disease Control and Prevention|Center for Disease Control and Prevention reported a cluster of Pneumocystis jiroveci pneumonia|Pneumocystis carinii pneumonia (now classified as Pneumocystis jiroveci pneumonia) in five gay men in Los Angeles in the early 1980s. http://www.cdc.gov/mmwr/preview/mmwrhtml/june_5.htm Originally dubbed GRID, or Gay-Related Immunodeficiency|Immune Deficiency, health authorities soon realized that nearly half of the people identified with the syndrome were not gay. In 1982, the CDC introduced the term AIDS to describe the newly recognized syndrome. Three of the earliest known instances of HIV infection are as follows: #A plasma sample taken in 1959 from an adult male living in what is now the Democratic Republic of Congo (Zhu et al., 1998). #HIV found in tissue samples from an American teenager who died in St. Louis in 1969. #HIV found in tissue samples from a Norwegian sailor who died around 1976. Two species of HIV infect humans: HIV-1 and HIV-2. HIV-1 is more virulent and more easily transmitted. HIV-1 is the source of the majority of HIV infections throughout the world, while HIV-2 is less easily transmitted and is largely confined to West Africa. (Reeves and Doms, 2002). Both HIV-1 and HIV-2 are of primate origin. The origin of HIV-1 is the Common Chimpanzee|Central Common Chimpanzee (Pan troglodytes troglodytes). The origin of HIV-2 has been established to be the Sooty Mangabey, an Old World monkey of Guinea Bissau, Gabon, and Cameroon. details|AIDS origin HIV is a 'social disease' with a specific social and economic impact. Infection with HIV-1 is dependent on many factcors including social status, gender, education, race, economic situation, age and occupation. A minority of scientists and activists question the connection between HIV and AIDS, or the existence of HIV, or the validity of current testing methods. These claims are met with resistance by, and often evoke frustration and hostility from, most of the scientific community, who accuse the dissidents of ignoring evidence in favor of HIV's role in AIDS, and irresponsibly posing a dangerous threat to public health by their continued activities. Dissidents assert that the current mainstream approach to AIDS, based on HIV causation, has resulted in inaccurate diagnoses, psychological terror, toxic treatments, and a squandering of public funds. The debate and controversy regarding this issue from the early 1980s to the present has provoked heated emotions and passions from both sides. details|AIDS reappraisal AIDS
Other references used in developing this article can be found at AIDS/references. wikinews|UN/WHO making progress in treating HIV/AIDS, but will miss 2005 target
Category:HIV/AIDS Category:Immune system disorders Category:Infectious diseases Category:Pandemics Category:Sexually-transmitted diseases Category:Virology af:VIGS ar:?????????????? ?????? ?????????????? ?????????????? be:???????? bg:???????? bm:Sida bs:AIDS ca:SIDA cs:AIDS da:Aids de:Aids als:AIDS es:SIDA eo:Aidoso fa:???????? fr:Syndrome d'immunod??ficience acquise ko:????????? hi:???????????? he:?????????? hr:SIDA sw:Ukimwi ku:AIDS lv:AIDS lt:AIDS hu:AIDS ms:AIDS nl:Aids ja:?????????????????????????????? no:AIDS nn:HIV/AIDS pl:Zesp???? nabytego niedoboru odporno??ci pt:S??ndrome da imuno-defici??ncia adquirida qu:SIDA ru:???????? sl:AIDS sk:AIDS fi:AIDS sv:AIDS sr:???????? ta:????????????????????? th:??????????????? vi:AIDS tr:AIDS uk:???????? zh:????????? simple:AIDS Link FA|fr Link FA|he Link FA|vi This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "AIDS".
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